Dervla Kirwan is reportedly set to star in the 2008 Doctor Who Christmas special. The Ballykissangel actress has been spotted on the set of the smash-hit sci-fi series in Cardiff, where the one-off episode is being filmed, The Sun reports. And it seems that the Doctor, played by David Tennant, will face some old enemies - the Cybermen are due to return for the feature-length episode, which is believed to have a Victorian theme. Locals spotted the steel men on location in a graveyard in Newport, Wales, the paper said. The news has sparked speculation that the 36-year-old Dervla will return as the Doctor's full-time assistant if Catherine Tate vacates the Tardis in this season's finale. Doctor Who's head writer, Russell T Davies, has confirmed that the franchise will return in 2009 Doctor Who with three specials starring Tennant. The full-length fifth series will transmit in 2010. Fans of the series will also see the return of Freema Agyeman as Martha Jones in the current series' fourth episode, which is due to be aired on April 26. The Sontaran Stratagem will show Martha calling the Doctor back to modern-day Earth to help battle an all too familiar monster.
